Alarm clock clapper retarder



Apnl 25, 1967 H. ODENBACH 3,315,460

ALARM CLOCK CLAPPER RETARDER.

Filed Sept. 20, 1965 2 Sheets-Sheet 1 FIG. I FIG. 2

April 1957 H. ODENBACH 3,315,460

ALARM CLOCK CLAPPER RETARDER Filed Sept. 20, 1965 2 Sheets-Sheet 2 United States Patent '0 3,315,460 ALARM CLOCK CLAPPER RETARDER Heinz Odenbach, Schwenningen am Neckar, Germany,

assignor t0 Kienzle Uhrenfabriken G.m.b.H., Schwenningen am Neckar, Germany, a limited-liability company of Germany Filed Sept. 20, 1965, Ser. No. 488,550 6 Claims. (Cl. 5821.12)

The invention includes a lever on the clap-per verge shaft of an alarmwork which lever has an end portion cammingly running in a laterally open groove or slot in an irregularly moved mass-body driven by said end portion as a varying inertia loss to slow down a clapper on the verge shaft. The groove is so shaped that at an end,

or end of a section, of the groove, there is little or no camming effect on the mass-body so that the lever and clapper are without appreciable restraint and then the clapper can freely complete a half swing onto a gong and bounce back, carrying the lever end portion back in the camming portion of the groove and then retard the reverse swing of clapper and lever. The mass body and groove may be designed for oscillatory or unidirectional turning or reciprocatory motion permitting one or more full swings of the lever during its period. The lever may be selectively disengaged from the verge shaft.

This invention relates to the ringer work of an alarm clock with variable clapper or striking frequency in which a lever fast on the ringer anchor or verge shaft is delayed in its movement by engaging in a groove in a supplementary mass-body.

Ringer works are known in which the running of the alarm works and consequently the clapper frequency are controlled by an element of the time work. As an example of this, a notched or star wheel mounted on the time wheel shaft controls a lever in operative combination with the ringer work train. As the ringer work runs down, the lever is disengaged from the time work and the ringer work operates at its own natural frequency. This type of construction is shown in German Patent 1,063,088. The disadvantage of this construction is that the control element is unreliable, a large number of parts is necessary, and the influence of the ringer work on the time work during the change of clapper frequency prevents the clock from keeping good time.

An air vanes delaying device that could be connected to and disconnected from the alarm work was later proposed but it met with little success.

Another known system operates by means of an added mass-body which is rigidly connected to the alarm hammer to reduce its striking frequency. Here too the running down of the ringer w-ork disengages the mass from the hammer, so that running frequency is determined only by the inertia of the clapper. Such a construction is shown in German Patent No. 817,869. The disadvantage of this arrangement is the relatively negligible decrease of the striking frequency resulting from the connection of the added mass.

Besides that, the clapper with the additional mass produces an undesirable buzzing noise, that is to say, a reliable striking of the clapper on the gong is not assured.

In the present invention there is a considerable reduction in hammer frequency obtained by an oscillatory 1ever mounted on the alarm anchor shaft or the clapper, and an end 'part of the lever engages in a groove in a movable mass-body. This construction is such that by action of the end part of the lever in the groove, during initial phases of each half swing, the body-mass is accelerated. If the clapper moves in one direction, say, toward the gong, the mass-body is accelerated anew from a rest position after the reversal of the direction of swing of the lever. The mass-body can be of difierent forms and shapes. For instance, it is possible that it be in the form of a turnable disk having a spiral shaped groove in; a side face or therethrough. A groove in the shape Of an Archimedes spiral is satisfactory. In the case of a; disk shaped mass body, grooves in the shape of other; curves are possible as will be shown herein later so that the disk turns in only one direction. It is also possible for the groove to be given such a shape that the massbody moves in a straight line. The oscillation lever. may be connected and disconnected periodically from the clapper means.

An object of the invention is to provide a means for slowing down clapper action.

Another object is to provide such means which will not influence the normal running of the clock and hence will not affect the accuracy of the time piece.

In the accompanying drawing showing, by way of example several of many possible embodiments of the invention.

FIG. 1 shows only one form of the invention, partly schematic;

FIG. 2 is a sectional view of the invention as shown in FIG. 1, the section being taken along the line 22 of FIG. 1, looking in the direction of the arrow of said line;

FIG. 3 shows a grooving of the disk so that the latter rotates in only one direction;

FIG. 4 shows the body in the form of a reciprocatory plate;

FIG. 5 shows another form of grooving for the plate;

FIG. 6 shows a roller for engagement in the grooving; and

FIG. 7 shows coupling mean-s to permit periodic disengagement of the mass-body members.

In FIG. 1 a clapper arm 1 having a hammer H is fast 7 on the ringer works verge or anchor shaft mounted for turning on a frame F2. The verge V mounted fast on the same shaft 2 engages with an escape or drive wheel E mounted, for example, near the shaft 2. Or, as shown in FIG. 7, the escape wheel may be loose on the shaft 2. Oscillation of the verge swings the arm 1 and the hammer strikes against the gong or bell portion 3 of a clock housing. East on the shaft 2 there is mounted a lever 4, whose somewhat hooked pin-like end 5 engages in a spiral shaped cam groove 6 of the turnable disk-like additional massbody 7. The disk-like mass is mounted for turning on an axle 8, fast on the frame of the clock and which is the turning point of the disk. When the ham-mer, and with it the lever, moves outwardly and according to the direction of the arrow A, the disk turns in clockwise direction. Thereby the disk shaped mass is gradually accelerated from rest. When the pin 5 has reached radially widened end 9 of the groove, then the clapper is able to swing freely over a short angular path and thereby strike against the gong and rebound. The disk formed mass maintains its direction of movement by its inertia.

Upon reverse movement of the clapper arm and the lever 4, the spiral groove is traced again by the end 5, but inwardly. This results in a forced reversal of movement of the disc according to the reversal movement of the lever, so that the turning in clockwise direction is stopped and so then the disk is accelerated in a counter-clockwise direction. Owing to the inertia of the disk 7 the reversal of movement of the clapper is markedly retarded at the inner reversal point, at or near the inner end ya of the groove.

The added mass-body 7' according to FIG. 3 is provided with a set of grooves having portions in the shape of a somewhat Archimedes spiral to form a closed Y track from three S curves 60, 6b, and 6a. As shown, the pin or hooked end 5 of the lever is in a reversal position 20 between reversal grooves and 12 of the S curve 611. Upon movement of the pin away from the center of the disk it follows along the portion of the curved groove 10 that has a convex bend. Thereby a movement 'of the disk in a clockwise direction is induced, and the pin passes into the junction 21 with the groove 6b. At the ends 11 of the curved groove 12, which is nearly radial, the clapper becomes free to swing. With this, the turning motion of part 7 is stopped. After the motion reversal of the pin 5, the latter follows the concave bend groove 12 until its motion is again reversed and then runs in the groove part 10. Thus the disk is accelerated, then retarded and again accelerated with the result of a certain variation of clapper frequency.

In FIGS. 4 and 5 the mass-body is not turnable but mounted for substantially linear motion or reciprocation. As shown, the pin 5 and lever 4 are at the inner point of reversal.

Upon movement of the clapper toward the gong the mass-body 13 is cammed and moved toward the right. When the pin reaches the end 15 of the groove 14, the clapper again becomes free to swing. Upon movement of the clapper away from the gong the direction of mo tion of the mass-body 13 is reversed. The mass-body 16 of FIG. 5, during vibration of the clapper moves toward the right. In the shown arrangement four delayed strokes are obtained.

FIG. 6 shows the pin provided with a roller 17 for engagement in the grooves in any form of the disclosed invention.

In all the forms illustrated thus far for the mass-body, the shape of the groove causes an acceleration of the massbody, and the latter is consequently an inertia load on the ringer work which tends to slow the work during a large part of the hammer cycle but without appreciable restraint when the hammer is about to strike the gong.

In a special form of the invention, shown in FIG. 1, the clapper arm 1, as shown in FIG. 7, is periodically freed from restraint due to the disk 7 so that the escape wheel E, operating on the verge V may oscillate the clapper arm 1 at higher speed and usually at greater amplitude. The escape wheel E is free to turn on the shaft 2, but the verge V, clapper arm 1, and a radial coupling lever 22 are fast on the turnable shaft 2. However, in FIG. 7 the lever 4a is mounted on the shaft 2 for free turning thereon, except when latched to the coupling lever in a manner described below.

The alarm spring wheel shaft 20 carries a control cam 21 friction-fitted thereon. The aforementioned ringer anchor shaft 2 here carries, free to turn thereon, the lever 4a which is restricted in movement, as was the lever 9, by the engagement with the mass-body 7. The massbody which here is shown as the turnable disk having -a spiral shaped groove 6 again has its turning point at 8 as in FIG. 1. A rocking catch 23 is mounted as at 28 for pivotal movement on the lever 4a, and has an outer free end 24 urged toward the control cam 21 by a tension spring 25 attached to the catch and lever 4a.

As shown, the system is in the locked state with the control cam 21 in position so that the lever 22 is in engagement with the catch and permitting seating of the lever 22 in the notch 26 of the catch. In this state the clapper is restrained by mass-body 5 through the lever 22, the catch 23 and the lever 4a. The ringing action is therefore very slow.

As a result of the cam 21 turning further in the direction of the arrow under the action of the unwinding alarm spring, the catch is cammed clockwise about the pivot 28 and out of its shown position and the lever 22 is disengaged from the catch 23. This means that the clapper can now move freely without restriction of the oscillatory disk 7 and produces a rash wak-ening sound. The control cam 21 is so proportioned, that from the beginning of the running of the alarm works to the time the shaft 21 has made about a three quarter turn the lever 22 and the latch are in engagement with each other. During the remainder of the turn, the dog 27 of the control cam works against the outer face 30 of the free end 24 of the catch.

In the locked state, that is to say when the latch and lever 22 are engaged with each other, the turning point of the alarm anchor, the notch or seat 26 and the pivot point of the latch on the lever 4a should form somewhat of a right angle.

In the unlocked state the catch face 15, and in the locked state, the free outer face 3!) should be concentric with the alarm anchor shaft 2.

In operation, assuming the alarm works are running and the system is in the state shown in FIG. 7 the rocker catch 28 effectively locks the clapper arm 1 so that the system operates as does FIG. 1. When the control cam 21 turns sufficiently to cam the rocker 23 off the end of the coupling lever 22 the verge operates the clapper without restraint, with the coupling lever 22 swinging back and forth. After the control cam has continued to turn until the rocker end 24 snaps off the dog 27 the rocker turns counter clockwise and the swinging coupling arm 22 is caught in the notch 26 to repeat the cycle.

It is to be noted that in FIGS. 1, 4, 5 and 7 the dynamic properties of the system are quite complex. Taking FIG. 1 as illustrative:

First the verge V of alarm clocks usually permit considerable movement of the clapper arm, second the verge of such a clock is usually biased by the clapper ball weight, or the like, to a go state such as to the left in FIG. 1.

The bias of the oscillatory system is generally such as to cause the bodies to assume theposition as shown.

In all cases the driving force of the verge is necessarily sufficient to overcome bias on the verge, and hammer rebound aids in preventing any dead center stalling of the mass oody as does any impact of the projection on the walls of the grooving to produce a bouncing action.

The invention claimed is:

1. An alarm clockwise having a frame, a gong, a turnable shaft on the frame carrying an alarm escape wheel, a verge and hammer system, a mass'body movably mounted for varying speed of movement on the frame and having a cam groove laterally open and having closed ends, a swing lever on the shaft and mounted to swing with the hammer system, the lever having a projection on the swing end thereof to move in an arc and engaged in the groove between the walls thereof, at least a portion of the groove being out of line with the direction of motion of the projection during swing of the swing lever and hammer system so that swinging of the lever will cam the body to move and provide an inertia load on the lever and hammer system for slowing the latter, an end portion of the groove being outwardly turned so that when the hammer nears the gong as a consequence of movement of the lever and body in a one-half swing,- engagement of the projection on the groove walls is less restrictive for swinging movement of the projection and hammer system to permit the hammer system to strike the gong without appreciable impedance of the mass-body.

2. A work as claimed in claim 1 wherein the massbody is a disk turnable above the center thereof and the groove having as major portions thereof segments of spiral shape in a face of the disk and said turned end portion of the groove being approximately radial.

3. A work as claimed in claim 1, said mass-body being a plate and mounted for substantially rectilinear movement and the groove therein having portions therein of constant slope relative to the rectilinear motion.

4. A work as claimed in claim 2, said groove being a continuous spiral groove to said radial turned end portion and the latter being of increased width.

5. A work as claimed in claim 2 said segments being six in number and joined in reverse fashion to provide three terminal ends to provide three dead portions wherein the projection may move without substantially cam- 5 ming the disk to rotate, said segments intercommunicating so that oscillatory motion of the projection tends to cam the disk to rotate in only one direction.

6. An alarm work as claimed in claim 1, said lever being loose in the shaft and wherein disconnectable coupling means are interposed between the verge and hammer system and the lever, means for biasing the coupling means to a coupled condition and means for periodically disconnecting the coupling means is dependence with the References Cited by the Examiner FOREIGN PATENTS 457,979 12/1936 Great Britain. 817,869 10/1961 Germany.

RICHARD B. WILKINSON, Primary Examiner. GERALD F. BAKER, Assistant Examiner. 

1. AN ALARM CLOCKWISE HAVING A FRAME, A GONG, A TURNABLE SHAFT ON THE FRAME CARRYING AN ALARM ESCAPE WHEEL, A VERGE AND HAMMER SYSTEM, A MASS-BODY MOVABLY MOUNTED FOR VARYING SPEED OF MOVEMENT ON THE FRAME AND HAVING A CAM GROOVE LATERALLY OPEN AND HAVING CLOSED ENDS, A SWING LEVER ON THE SHAFT AND MOUNTED TO SWING WITH THE HAMMER SYSTEM, THE LEVER HAVING A PROJECTION ON THE SWING END THEREOF TO MOVE IN AN ARC AND ENGAGED IN THE GROOVE BETWEEN THE WALLS THEREOF, AT LEAST A PORTION OF THE GROOVE BEING OUT OF LINE WITH THE DIRECTION OF MOTION OF THE PROJECTION DURING SWING OF THE SWING LEVER AND HAMMER SYSTEM SO THAT SWINGING OF THE LEVER WILL CAM THE BODY TO MOVE AND PROVIDE AN INERTIA LOAD ON THE LEVER AND HAMMER SYSTEM FOR SLOWING THE LATTER, AN END PORTION OF THE GROOVE BEING OUTWARDLY TURNED SO THAT WHEN THE HAMMER NEARS THE GONG AS A CONSEQUENCE OF MOVEMENT OF THE LEVER AND BODY IN A ONE-HALF SWING, ENGAGEMENT OF THE PROJECTION ON THE GROOVE WALLS IS LESS RESTRICTIVE FOR SWINGING MOVEMENT OF THE PROJECTION AND HAMMER SYSTEM TO PERMIT THE HAMMER SYSTEM TO STRIKE THE GONG WITHOUT APPRECIABLE IMPEDANCE OF THE MASS-BODY. 